I could have sworn this thread was about WRXs and not STIs, concerns about ringland issues, and questions about this lean issue which so many blame on the ringland failures. If that's the case, here's a dyno plot of a stock 2011 WRX from Cobb. Note the AFR compared your STI dyno.

I for one would like to see a dyno graph from and independent company or person. No offense to Cobb but they are selling a product and marketing it as safer than stock. I hope someone jumps in and posts said dyno graph...